In his/her daily work a dentist must use a mouth mirror to enable him/her to see everywhere inside the oral cavity. A conventional mouth mirror consists of a narrow handle with a circular mirror attached to one end. The mirror surface is usually angled in relation to the axis of the handle in order to facilitate inspection of all surfaces of the teeth.
The water cooling the high-speed drill is a considerable problem since it deteriorates vision in the mirror. The surface of the mirror is also contaminated by condensation, drill chips and saliva. The cooling water must also be removed by a special suction device since the conventional saliva suction device is insufficient. Since one of the dentist's hands is holding the mirror and the other the drill, a nurse usually assists with a suction device which helps to maintain clear vision on the mouth mirror.
It is known to remove foreign substances from the mirror with the aid of centrifugal force on rotating mirrors. European patent 0 387 216 A1 describes such an arrangement. It shows a mirror provided with a turbine and operating by compressed air. Foreign substances and water are not removed from the oral cavity, only from the mirror.
British patent specification GB 1 255 719 shows cleaning of the mirror with water jets, the water then being evacuated by vacuum suction. A dependent claim also talks of a mirror with rotation which, according to the description, is obtained from compressed air that can operate a small turbine.
The compressed-air operation in the known solutions entails complicated constructions and expensive installation costs. Many dentists therefore refrain from this equipment and instead use a conventional dentist's mirror without any self-cleaning.